Process for aging azoic printed fabrics



United States Patent 9 Trion, Ga., assignors to Riegei'Texfiie Corporation, a corporation of Delaware No Drawing. Application'July 6, 1955, Serial-No. 520,353

1 Claim. (Cl. 8-71) This invention relates to printing and developing of colors or colored designs on textile fabrics, and more particularly to an improvement in the aging 'or developing treatment-of the previously printedfabrics.

One of the features of the improved process of this invention is a preliminaryor partial aging of the printed textile fabric immediately after printing and drying of the fabric, whereby'any'defects occurring in the printing-operation (which would not normally appear until the printed fabric had been completely aged or developed at a later stage in the manufacturing process) become apparent immediately in the parti'allyaged goods such that correction of the defects can be made before any substantial yardage of the defective goods has been produced.

Another' commercially advantageous feature of the process of this invention is the continuation of the above mentioned-partial aging or developing of the color during the period of time between thepreliminary aging and the final aging wherebysubstantial saving of time and chemicals normally required for the complete aging process is realized.

Thetwo above mentioned features, as well as associated benefits that characterize the process of this invention, have materially'afieeted the economics of the printing-and aging operation'as normally carried out in a tex-- tile printmill. For example, the feature of detecting immediatelydefects in the printing operation results in a saving'of hundreds, and sometimes thousands of yards of cloth that have been improperly printed but the defects in which are not discovered until the printed cloth has accumulated in large amounts and until the aging or developing treatment has been completed. At that stage, the amount of defective goods has oftentimes re'a'ched'a very high yardage and, consequently, a very-high loss in first quality goods.

By the process of the present'invention, the above mentioned substantial losses, which are commonplace in the industry, are eliminated. By inspection of the partially aged goods, which takes place immediately afterdrying of the printed goods, any defects become clearly visible to an inspector, who then stops the printing operation after only a few yards of cloth have been printed.

It will be understood that this substantial benefit in detectingimmediately any defects in the printed cloth, applies to printing colors that require aging or developing on the cloth after printing to render the color or design visible, or.at least easily distinguishable. These colors include generally the solubilized vat dyestuffs, such as those-sold under the'trade names Algosol and Indigosol; the insoluble azo dyestuffs such as the Rapidogens manufacturedby General Dyestufi, Spectrolenes manufactured by Hilton Davis. 'Co., Pharmosols produced by the Pharma ChemicalCorp Diagens manufactured by E. I. Du'Pont (30., Calconyls manufactured by American @aiiamidCcimpanwMetrogens produced by Metro Atlitlliiflflfifi; andaniline bla'ckcolors, produced by Aineriice can Cyanamid Company. As is well. known,- these types of dyestuffslrequire aging or developing with steam .and/ or acid vapors to obtain the desired color or colored pattern previously printed on the fabrics, using one or more of these dyestuffs.

The aging or developingprocess is usually carried out in a large, closed, acid-resistant chamber commonly known as an ager,, and inwhich the previously printed cloth is subjected to the action of steam or acid vapors at elevated temperatures. The printed cloth is conducted through the ager in a tortuous path, e. g., festooning, andlremains in the ager under these conditions for a sufiicient length'of time to age or develop the color and produce the desired color combinations or patterns on the printed cloth.

This conventional aging or developing operation may ultimately be carried out in the usual manner, in the process of the present invention, but after the printed cloth has been preliminarily or partially aged for a very short period of time suflicient to detect defects in the printing 'operationas above described. Also, by using the preliminary partial aging procedure of this invention, and permitting the partially aged goods to dwell or rest for an appreciable length of time before final aging, the time of final aging in the regular commercial aging equipment has been reduced as much as 25 percent, or more. In addition, the amount of chemicals used, e. g., acetic acid or formic acid, has been reduced as much as 40 percent or more, and this refers to the total amount of chemicals used in the preliminary aging and in the final aging treatment.

We have discovered, in accordance with the present invention, that if the preliminarily, partially aged, printed goods are permitted to remain in storage, such as, for example, in .the'storage boxes commonly used in printing mills, for an appreciable length of time, such as 12, 24 or 48 hours, this preliminary, partial aging continues or progresses during the storage period, with the net result that the'printed'goods are substantially completelyaged at the end of this storage period. This benefit is obtained without the use of heat or acid fumes.

For the purpose'of obtaining uniformity'and assuring a complete aging of the colors, the goods which have been preliminarily aged and further developed under static conditions, in accordance with our process, are subsequently carried through the regular aging treatment, but fora substantially shorter length of time than is normally requiredfor this final aging.

The process of our invention may be applied to various types of textile fabrics, composed of synthetic or natural fibers, and including the well known broadcloth, poplin. twill, flannelette, naped fabric, canton flannel, .etc. Typical-weights for these types of fabric are 3.75 yards per pound for fiannelette; 4.0-4.5 and 5.0-5.35 yards per pound for broadcloth; 2.85 yards per pound for twills and 1.7 5-2.0 yards per pound for poplins.

The following are illustrative but'non-limiting examples of the'pro'cess of our invention whereby the benefits of promptly detecting printing defects, and of substantial reduction in the'over-all cost of the aging treatment, are

realizedf Example 1 Cloth:

White flannelette ll/eight 3.75 (40" x 44") Finished Width 35 3 6" Print patter-n5 Spaced red and'yellow stripes 3 Dyestuft':

Rapidogen Spectrolene Red AS & KB. Insoluble stabilized azoic naphthol No. Pr. 270 H Spectrolene Yellow G. S. Insoluble stabilized azoic naphthol, identified as follows:

Base: Red KB (p chloro-o-toluidine hydrochloride) Stabilizer: s (sarcosine) Coupling component: Naphthol AS-G (4,4-bio-acetoacetotoluidide) N0. Pr. 1'71 Manufactured by Hilton Davis Co., Greenville, S. C.

Procedure-The white fiannelette cloth, in continuous Web form, was fed through the cloth printing machine in conventional manner, and the printing roll applied the above identified Rapidogen dyestuffs in wide separate bands running the length of the cloth. These difierent colored bands were only faintly visible on the freshly printed cloth. The wet printed cloth web upon leaving the printing machine was run continuously over heated drying cans that substantially dry the cloth.

At this stage the red and yellow colors are not fully developed and if defects in the printing operation have occurred, such as a smearing of the dye by a defective doctor blade on the printing machine, the resulting imperfections in the printed cloth would not be readily apparent and would likely go unnoticed until the printed cloth had subsequently passed through the regular ager. In usual commercial practice the printed and dried cloth would be plaited, folded loosely, and stored in movable boxes until some substantial yardage of the cloth was produced and then removed to the ager and run through that machine for aging or developing the red and yellow colored stripe design on the cloth.

However, in carrying out the process of the present invention, the printed and dried cloth is immediately run through a preliminary or partial aging machine located adjacent the cloth drying cans. in fact, the operation .is continuous and the dried cloth passes directly through the miniature ager and at substantially the same speed as it runs through the printing machine and over the drying cans.

This miniature or partial ager is similar to the conventional or usual commercial size ager in which the cloth is passed back and forth, in festooning manner, in a closed chamber in which the atmosphere contains a mixture of steam and acetic acid vapors. A typical size miniature ager which we have found very satisfactory is about 3 feet high by about 4 feet Wide and 1 foot in depth. The previously printed and dried cloth is festooned through this ager at a rate such that the cloth remains in the ager for only about 30 seconds. During this short time the cloth becomes saturated with the steam and acetic acid fumes in the ager, which develop the colors on the printed cloth so that as the cloth leaves the ager and is folded in a box, the printed pattern is clearly apparent. Thus an inspector watching the cloth leaving the ager will detect immediately any appreciable imperfections in the printing and will stop the printing machine for necessary adjustments.

The cloth treating conditions in the miniature ager are similar to those that have been used in the regular or final ager heretofore, but when used in the miniature ager eitect quite a substantial saving in the amount of chemicals and in the usual time requirement for complete aging of the goods in the regular ager. Although formic acid or acetic acid either may be used in the miniature ager, it is oftentimes advantageous to use acetic acid. When purchased in the usual commercial purity and concentration, the acetic acid is first diluted with water in the ratio of about 1 gallon of acetic acid to 1 gallon of water. This dilute aqueous solution of the acetic acid is introd ced into the miniature ager along with live steam, and we have found it advantageous to efiect a pred liminary mixing of the steam and the dilute acetic acid solution before it enters the miniature ager.

In a typical operation of the miniature ager, approximately 10 gallons of the above mentioned dilute aqueous acetic acid is used in the miniature ager in 24 hours. This dilute aqueous acid may be admixed with the steam in the ratio of about 1 part of dilute acid to 10 parts of steam, and the resulting concentration of acid to water vapor in the miniature ager is in the ratio of about 1 part of acid to 25 parts of water vapor.

The time of treatment of the printed cloth in the miniature ager will vary, with different types of dyestuffs used, from about 20 seconds to 60 seconds, with an average or typical treating time of about 30 seconds. Ti is treating time constitutes only a fraction of the treating time in the usual commercial size ager, of about 2 to 3 minutes. Also, when the miniature ager is used for obtaining partial or preliminary aging of the printed goods, the above mentioned usual time of 2 to 3 minutes for the regular large ager is reduced to about 1 /2 to 2% minutes. Additionally, the concentration of the acetic acid vapor in the regular large ager may be reduced from the usual concentration of about 1 part of acid to 25 parts of water vapor, to a concentration of about 1 part of acid to parts of water vapor, when the final aging follows a preliminary aging in accordance with this invention.

Another important aspect of the preliminary aging treatment of the present invention is the change in the pH of the printed goods, particularly the dyestufis printed thereon, from an initial strongly alkaline pH, before printing, of about 10 to 12, to an acid pH of about 4. This change in pH which is produced in the goods during the short treating time in the miniature ager is conducive to aging or developing of the colors on the goods, and is eifected by the action of the acid vapors in the miniature ager.

The cloth which has been printed, dried, partially aged and inspected, and stored in a box, is permitted to remain in this box for a period of hours, perhaps overnightor even over a weekend before it is run through the final ager. It is during this delay or storage time that the acid fumes remaining in the cloth effect a progressive aging or developing of the color. In some cases the developing of the color is practically complete at the end of the storage time and before the cloth has entered the final full size ager.

Example 2 Cloth:

White flannelette Weight 3.75 (40" x 44") Finished Width 35"36" Print pattern: Spaced green and blue stripes Dyestulf:

Soluble vats Algosol Blue 04B Lenco vat ester Color Index No. 1184 Algosol Green IBW Lenco vat ester Color Index No. 1101 Pr0cedure.-The procedure for printing this pattern is generally the same as that described under Example 1 above. When the cloth is first printed on the printing machine with the two different colored dyestuifs, namely, the Algosol blue and the Algosol green, the designs are not clearly apparent immediately after the printing or even after the drying of the printed cloth, this being particularly true of the Algosol blue color. However, upon treating of the printed cloth in the miniature ager, both the blue and green colors are developed and clearly defined so that any imperfections in the patternwill become immediately apparent and the printing operation can be stopped to avoid any substantial loss of goods due to defective printing.

Here, as in Example 1 above, the two printed line patterns are gradually and progressively developed during the storage period, following the treatment of the cloth in the miniature ager, and prior to the final aging or developing in the full size ager.

Pracedure.-The same procedure described above under Examples 1 and 2 is followed in this case, in which only one color dyestufi, namely, aniline black, is used for printing the spaced line design. The aniline black dyestulf is scarcely visible on the cloth following the printing operation but becomes distinctly and sharply visible on the cloth following the treatment in the miniature ager so that defects in printing can be immediately observed and the operation stopped. Also, the progressive aging or developing of the aniline black dyestuff takes place, during the delay between the miniature ager and the final ager, as above described. The final aging in the regular full size ager renders the pattern more clearly distinct or more sharply defined and assures full development of the cloth.

The aniline black dyestufi mentioned in the above example is prepared just prior to use, and in conventional manner, by mixing 3 parts of aniline salt with 2 parts of prussiate of soda and 1 part of chlorate of soda. This mixture, when applied to the cloth, does not produce a typical aniline black color, for the latter is obtained only when the cloth printed with this aniline dyestutt mixture is dried and then brought into contact with the acetic acid and steam vapors in the miniature ager.

One of the most common defects encountered in the printing operations as above described, results from accumulation of dyestuif or lint or other foreign matter on the doctor blade which is conventionally used on the printing machine to remove the excess dyestufi from the printing roll. If the doctor blade does not wipe the roll smoothly and uniformly, or some collection of dyestufl or waste material occurs at some place on the doctor blade, it will produce smears of the dyestufi on the cloth which are commonly known in the trade as fsnaps, drags or chatter. This defect in the doctor blade operation can oftentimes produce a sizable smear or mark of the dyestuff across the face of the fabric and render it entirely unsalable, and unless the dyestuff is developed in the minature ager, the defect does not show up until many yards of the cloth have been run and the cloth is finally aged in the regular ager.

The foregoing are typical but only illustrative examples of the printing operations that are commonly carried out in printing of piece goods and in which the advantages of the present invention may be utilized for eliminating substantial losses in defective printing and for obtaining substantial savings in the amounts of chemicals required for developing the printed patterns on the cloth. Substantially the same aging conditions above described for flanuelette cloth, may be used for broadcloth, twills, poplins, etc.

The dyestuffs that are used are dyestuffs commonly employed in producing print goods and are used in the form of print pastes prepared in conventional manner, using the desired amounts of dyestuffs along With fillers and other constituents commonly employed in making up the printing paste. The amount of dyestuff used in the printing paste will vary widely depending on the color concentration desired in the printed goods. For example, when a concentrated, or full strength color is desired, about 8 ounces of dyestufi would be used to 1 gallon of the printing paste. However, where a pastel, or very light color is desired, the dyestufi concentration in the paste would be substantially reduced, such as, for example, about 8 ounces of color to 2()0 gallons of paste. A typical filler material for the print paste is starch, which may be used in an amount of about 1 part of starch to 1 gallon of paste. A typical resin filler would consist of about 2 gallons of resin dispersed in 33 gallons of solvent, and mixed with 66 gallons of water. A lubricating oil to effect good running of the paste in the print machine, as well as other additives, may also be included in the printing paste.

It will be understood that dyestufis which do not require developing or aging, such as pigment dyes, will not require the preliminary aging of our invention, although such dyestuffs might be used in combination with or concurrently with other dyestuffs that do require aging or developing and which benefit from the preliminary aging process of this invention.

Various modifications and changes in the materials and conditions described herein above may be made Without departing from the scope of our invention as defined in the appended claim.

We claim:

In the printing of textile fabrics with insoluble azo colors that require development by steam and acid treatment, the improvement which comprises training a printed fabric continuously from a printing station past a preliminary treatment station at the printing speed, and treating the fabric at such preliminary treatment station with steam at atmospheric pressure and dilute acid for a period of about 20 to 60 seconds, sufiicient only to develop partially the color pattern for making the pattern visible and thereby disclosing possible defects in the printing, storing the partially developed printed fabric for a period of hours sufficient to permit the acid remaining therein to efiect a progressive further development of the color pattern and finally subjecting the fabric to a further acid and steam treatment to develop fully the printed pattern.

Amer. Dye. Reporter for December 12, 1949, pages P919-P922. 

